1. Field of the invention
The present invention relates to a safety injection device, and more particularly to a safety injection device having a plunger, a stopper adapted to be mated with the plunger and a seat movably received a barrel and having a needle cannula securely mounted thereto. The plunger together with the stopper is able to move the seat in the barrel to a first position where the seat is stationary and the needle cannula extends out from the locking tip of the barrel and a second position where the needle cannula is entirely received in the barrel, therefore, hazard of infection by the used needle cannula and even injury is avoided.
2. Background of the invention
Nurses, doctors or even environmental recyclists all treat hospital waste as extremely hazardous, especially radioactive waste and hypodermic needles. Radioactive waste is hazardous because of the radiation, and the hypodermic needles are hazardous because the contaminated cannulas can infect people with fatal diseases. To avoid injury and exposure to disease from used needles, attendants often use a small cap disengagably attached to the top of the barrel to enclose the sharp tip of the needle. However, during the process of placing the cap on the needle, people are exposed to germs and virus if the skin is inadvertently pierced. To prevent such a tragedy from happening, a safety device is introduced into the market, which enables people who takes care of the needle to dispose of the needles quickly and safely. The device is a box-like device with which a user is able to disengage the needle cannula from the barrel and securely hold the needle cannula therein, such that attendants will not think handling used needles is a frightening job. Indeed, the box-like safety device ensures the safety of the attendants, but it also causes another kind of pollution to the environment. The safety device is a separate part from the needle, which means that manufacturers will have to produce and store it separately. Furthermore, once the device is used, it cannot be recycled. It will be discarded, which increases the social burden to deal with the waste. Therefore, the invention intends to introduce a safety injection device to mitigate and/or obviate the aforementioned problems.